Refactor and extend tests

[christophfroehlich]

For #199 I wrote new tests, which are also applicable for KDL.

For easier review:
In a first step, I propose to add the new testcases to the old file. As an upcoming step, I'd use a templated test file to be used by all implementations.

[codecov]

Codecov Report

❌ Patch coverage is 98.68421% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 88.19%. Comparing base (4a831a8) to head (1f9c887).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
...ics_interface_kdl/src/kinematics_interface_kdl.cpp	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #210      +/-   ##
==========================================
+ Coverage   86.64%   88.19%   +1.55%     
==========================================
  Files           4        4              
  Lines         277      305      +28     
  Branches       60       53       -7     
==========================================
+ Hits          240      269      +29     
  Misses         21       21              
+ Partials       16       15       -1     

Flag	Coverage Δ
unittests	88.19% <98.68%> (+1.55%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...lude/kinematics_interface/kinematics_interface.hpp	100.00% <ø> (ø)
...terface_kdl/test/test_kinematics_interface_kdl.cpp	100.00% <100.00%> (ø)
...ics_interface_kdl/src/kinematics_interface_kdl.cpp	81.95% <66.66%> (+1.18%)	⬆️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[Copilot]

Pull Request Overview

This PR refactors and extends the test suite for the KDL kinematics interface by adding new test cases, improving test readability with custom matchers, and enhancing error messages. The changes prepare for future test templating across implementations.

Key changes:

• Added custom GoogleTest matchers (MatrixNear, DoubleNear) to replace manual element-by-element comparisons
• Added new test cases for reduced kinematic models (testing both reduced tip and base configurations)
• Improved error logging by adding RCLCPP_ERROR messages for verification failures and enhancing existing error message formatting

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

File	Description
kinematics_interface_kdl/test/test_kinematics_interface_kdl.cpp	Refactored test helper methods to accept parameters, added new test cases for reduced models and frame difference calculations, replaced manual assertions with custom matchers
kinematics_interface_kdl/src/kinematics_interface_kdl.cpp	Added detailed error logging for input verification failures, improved error message formatting with quotes, fixed logic for empty base parameter handling
kinematics_interface/include/kinematics_interface/kinematics_interface.hpp	Added cross-platform FUNCTION_SIGNATURE macro and Vector6d type alias for improved code reusability

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[Copilot]

Pull Request Overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}